17
H.-J. Ceccaldi et al. (eds.), Marine Productivity: Perturbations and Resilience of Socio-ecosystems,
DOI 10.1007/978-3-319-13878-7_2, © Springer International Publishing Switzerland 2015
H. Takami (*)
Tohoku National Fisheries Research Institute ,
Fisheries Research Agency , 3-27-5, Shinhama ,
Shiogama , Miyagi 985-0001 , Japan
e-mail: htakami@affrc.go.jp
H. Nakaie
Miyagi Prefectural Government , 3-8-1 Honcho,
Aoba-ku , Sendai , Miyagi 980-8570 , Japan
Abstract
On 11 March 2011, a massive tsunami generated by a mega-earthquake hit
a wide area of the Pacifi c coast of northeast Japan. We have analysed the
effects of the tsunami on Ezo abalone Haliotis discus hannai population at
Iwaisaki in Miyagi, Japan. Ezo abalone is among the most economically
valuable fi sheries resources, so assessments are needed to evaluate the
effects of the disaster on this important species. Before the tsunami, algal
forests dominated by the brown macroalga Eisenia bicyclis had developed
in the survey area, where large juvenile and adult abalone >30 mm in shell
length (SL) inhabited. Juvenile abalone <30 mm SL inhabited the area
dominated by crustose coralline algae (CCA). After the tsunami, no apparent decrease was observed in the density of large juvenile and adult abalone inhabited in the algal forests. The impact of the tsunami was more
profound in the CCA area than in the algal forests. Just before the tsunami,
the intensive recruitment of zero-year-old juveniles was observed, but
individuals of this year class were not detected after the event. The distribution pattern of juveniles could be a cause of the marked decrease,
because most of them inhabited the CCA area where the disturbance by
the massive water movement was not reduced by the effects of the macro
algal forest. Since the age at fi rst capture of abalone is at 4–5 years old, the
future commercial catch may considerably decrease for at least 4–5 years
after the tsunami.
Impacts of the 2011 Megaearthquake and Tsunami on Ezo
Abalone Haliotis discus hannai
at Iwaisaki, Miyagi, Japan
Hideki Takami and Hiroshi Nakaie
1
Introduction
On 11 March 2011, the Great East Japan
Earthquake occurred off the Pacifi c coast of the
northeastern part of Honshu Island, Japan, with a
moment magnitude of 9.0 at a depth of 24 km.
The massive tsunami generated by this earthquake
severely impacted the coast of northeastern
H.-J. Ceccaldi et al. (eds.), Marine Productivity: Perturbations and Resilience of Socio-ecosystems,
DOI 10.1007/978-3-319-13878-7_2, © Springer International Publishing Switzerland 2015
H. Takami (*)
Tohoku National Fisheries Research Institute ,
Fisheries Research Agency , 3-27-5, Shinhama ,
Shiogama , Miyagi 985-0001 , Japan
e-mail: htakami@affrc.go.jp
H. Nakaie
Miyagi Prefectural Government , 3-8-1 Honcho,
Aoba-ku , Sendai , Miyagi 980-8570 , Japan
Abstract
On 11 March 2011, a massive tsunami generated by a mega-earthquake hit
a wide area of the Pacifi c coast of northeast Japan. We have analysed the
effects of the tsunami on Ezo abalone Haliotis discus hannai population at
Iwaisaki in Miyagi, Japan. Ezo abalone is among the most economically
valuable fi sheries resources, so assessments are needed to evaluate the
effects of the disaster on this important species. Before the tsunami, algal
forests dominated by the brown macroalga Eisenia bicyclis had developed
in the survey area, where large juvenile and adult abalone >30 mm in shell
length (SL) inhabited. Juvenile abalone <30 mm SL inhabited the area
dominated by crustose coralline algae (CCA). After the tsunami, no apparent decrease was observed in the density of large juvenile and adult abalone inhabited in the algal forests. The impact of the tsunami was more
profound in the CCA area than in the algal forests. Just before the tsunami,
the intensive recruitment of zero-year-old juveniles was observed, but
individuals of this year class were not detected after the event. The distribution pattern of juveniles could be a cause of the marked decrease,
because most of them inhabited the CCA area where the disturbance by
the massive water movement was not reduced by the effects of the macro
algal forest. Since the age at fi rst capture of abalone is at 4–5 years old, the
future commercial catch may considerably decrease for at least 4–5 years
after the tsunami.
Impacts of the 2011 Megaearthquake and Tsunami on Ezo
Abalone Haliotis discus hannai
at Iwaisaki, Miyagi, Japan
Hideki Takami and Hiroshi Nakaie
1
Introduction
On 11 March 2011, the Great East Japan
Earthquake occurred off the Pacifi c coast of the
northeastern part of Honshu Island, Japan, with a
moment magnitude of 9.0 at a depth of 24 km.
The massive tsunami generated by this earthquake
severely impacted the coast of northeastern